The Progreso Pier, located on the northern coast of the Yucatán Peninsula, is an exemplary case of durable concrete infrastructure. Designed and con-structed in 1935 by the Danish firm Christiani & Nielsen, it represents one of the earliest applications of durability-based design in marine environments. The pier¿s structure integrates massive concrete elements and stainless-steel components in both the substructure and superstructure, optimizing resistance to corrosion and mechanical degradation. Christiani & Nielsen¿s approach minimized the use of conventional steel to mitigate corrosion-related maintenance. Their design accounted for local environmental exposure and utilized regional materials, including porous limestone aggregates, to achieve both economy and resilience. After 85 years of service, the pier demonstrated remarkable durability due to its innovative use of stainless steel (type 304) and concrete mass design. Between 2002 and 2013, inspections by the Mexican Institute of Transportation (IMT acronym in Spanish), CINVESTAV-IPN identified structural deterioration. From 2002 to 2013, inspections of the Progreso arched viaduct documented progressive cracking, load-induced tensile stresses, and support movements caused by increasing heavy traffic. Despite extensive CFRP strengthening, damage continued, confirming that the structure reached its load capacity and requires load reduction or a parallel alternative viaduct. As a result of this study, in 2013 the Mexican government authorized the design of a new viaduct using durable concrete intended to resist chloride penetration over an 80-year service life. Although the use of stainless-steel reinforcement was not approved for economic reasons, the new viaduct was completed in 2017. Further studies are recommended for the old viaduct to refine rehabilitation methods, including evaluating CFRP strip applications for crack attenuation and long-term structural performance.
